Measuring the speed of electromagnetic wave propagation in a fluid within a conduit

A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:

• acquiring, at each of a number of instants of time from each antenna of an array of at least two antennas distributed at predetermined locations along a conduit, spatio-temporally-sampled data for electromagnetic (EM) wave propagation through a fluid in the conduit, the at least two antennas operating at transmitted frequencies that are above a first cutoff frequency of the conduit;
• generating, based on the spatio-temporally-sampled data and using a spectral-based algorithm technique, a k-ω plot plotting curves having a kinematic relationship relative to an angular frequency of a spectral component of EM disturbances, a wavenumber, and a speed of the EM wave propagation;
• identifying, using the k-ω plot, a spectral ridge on the curves, and determining parameters for calculating a slope of the spectral ridge;
• determining, using the spectral ridge on the curves and the parameters the slope of the spectral ridge;
• determining the speed of EM wave propagation assuming a relation between the speed of EM wave propagation and the slope of the spectral ridge;
• determining, using the speed of EM wave propagation and the slope of the spectral ridge, components of the fluid flowing in the conduit;
• and
• controlling wellbore operations based on the components of the fluid flowing in the conduit.

A computer-implemented system, comprising:

• one or more processors;
• and
• a non-transitory computer-readable storage medium coupled to the one or more processors and storing programming instructions for execution by the one or more processors, the programming instructions instructing the one or more processors to perform operations comprising:
• acquiring, at each of a number of instants of time from each antenna of an array of at least two antennas distributed at predetermined locations along a conduit, spatio-temporally-sampled data for electromagnetic (EM) wave propagation through a fluid in the conduit, the at least two antennas operating at transmitted frequencies that are above a first cutoff frequency of the conduit;
• generating, based on the spatio-temporally-sampled data and using a spectral-based algorithm technique, a k-ω plot plotting curves having a kinematic relationship relative to an angular frequency of a spectral component of EM disturbances, a wavenumber, and a speed of the EM wave propagation;
• identifying, using the k-ω plot, a spectral ridge on the curves, and determining parameters for calculating a slope of the spectral ridge;
• determining, using the spectral ridge on the curves and the parameters the slope of the spectral ridge;
• determining the speed of EM wave propagation assuming a relation between the speed of EM wave propagation and the slope of the spectral ridge;
• determining, using the speed of EM wave propagation and the slope of the spectral ridge, components of the fluid flowing in the conduit;
• and
• controlling wellbore operations based on the components of the fluid flowing in the conduit.